The Talin were bipedal, with long arms and legs, and a small vestigial tail. They had oval-shaped heads by large yellow eyes, and a large lipless mouth with small, sharp teeth. Their pebbled skin was colored green in their young (who were born live), and turning reddish as they mature. Adult Talin could also change skin coloration, the males toward the red end of the spectrum, and females toward the blue. The males also displayed a high crest of hair that ran in a stripe from their heads down mid-back. In females, the hairs were shorter and extended only to the back of the neck.
Talin had a unique ability to create a hibernation shell, or cocoon, which originally served to protect them during periods of extreme seasonal change, such as the dry desert season. However, as the Talin became more technologically advanced, this ability became less culturally acceptable, and only used in cases of extreme trauma or injury.
The Talin used eighteen different major languages, with 227 dialects.
By the mid 23rd century, the Talin developed television, in a form similar to that developed on 20th century Earth and contemporary Magna Roma. They broadcast at least 300 audiovisual channels, in addition to over 5000 audio-only, broadcasting news and cultural content.
The Talin were divided into several nation-states. The most powerful was located across the equatorial desert on Talin's primary continent; they were called "the Browns" by Starfleet's First Contact Office, due to the color used as their national identifier. The second most powerful were called "the Greens", and comprised a five-state union on the secondary continent, in a temperate forest and grassland region. The two nations, though differing in only minor respects, formed a rivalry that was described as being primarily emotional in nature.
Circa the mid 2250s, Talin science discovered a method of nuclear fission, which was applied to nuclear weaponry. These initial experiments apparently attracted an ancient, primitive lifeform dubbed "the Many", which then began manipulating Talin technology in an effort to increase political tensions and provoke a large release of atmospheric radiation. These beings and their intentions were unknown to the Talin, although their militaries were able to detect several in flight in their atmosphere.
Circa 2270, the Talin detected a different extraplanetary craft: a Federation Wraith-class shuttle, operated by the First Contact Office out of their outpost on Talin's moon. Not long after, the Brown and Green nations launched a joint mission to the moon, manned by Seerl ti'La and Orr ni'Li, to investigate the suspected alien presence there.
Shortly after, an accidental nuclear detonation in a weapons silo in the Green nation led to the automatic exchange of missiles between the Greens and Browns. Unknown to the Talin at the time, the USS Enterprise was in orbit, and acted to destroy or disarm all the weapons in flight. This outcome was quickly termed the Blue Season Miracle by the Talin, and led to disarmament agreements between the two nations.
However, approximately three days later, a massive exchange of missile weapons was triggered by the Many, devastating the planet and killing approximately half a billion of the planet's two and a half billion population. Fortunately, those who survived the initial blasts were able to survive for months after by cocooning themselves.
Following the exchange, FCO personnel revealed themselves to Seerl and Orr, still in lunar space, and took them to safety. Months later, they appeared before the Federation General Council, presented as the ambassadors from Talin IV, in a bid to have the Federation's Prime Directive restrictions lifted from their world and to receive Federaton aid. Between this appeal, and the discovery of the earlier alien interference by the Many, Talin IV was deemed not to be subject to Prime Directive restrictions, and was recognized as a member of the United Federation of Planets. A massive aid effort was then sent underway. (TOS novel: Prime Directive)